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A233868 Numbers that are not the sum of two evil numbers. 0
1, 2, 4, 7, 31, 127, 511, 2047, 8191, 32767, 131071, 524287, 2097151, 8388607, 33554431, 134217727, 536870911, 2147483647, 8589934591, 34359738367, 137438953471, 549755813887, 2199023255551, 8796093022207, 35184372088831 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
2, 4 together with A083420. - R. J. Mathar, Dec 22 2013.
Also, numbers that are not the sum of two distinct odious numbers. - David Radcliffe, Jul 21 2016
LINKS
FORMULA
From Chai Wah Wu, Aug 02 2020: (Start)
a(n) = 5*a(n-1) - 4*a(n-2) for n > 5.
G.f.: x*(12*x^4 - 5*x^3 - 2*x^2 - 3*x + 1)/((x - 1)*(4*x - 1)). (End)
CROSSREFS
Cf. A000069, A000668, A001969, A083420, A175611 (primes that are not the sum of two positive evil numbers).
Sequence in context: A102125 A102124 A280713 * A295125 A082537 A004577
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
Terms corrected by R. J. Mathar, Dec 22 2013
STATUS
approved

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Last modified May 20 08:57 EDT 2024. Contains 372710 sequences. (Running on oeis4.)